Hydraulic control mechanism for road machines



G. P. GREEN Sept. 27, 1955 HYDRAULIC CONTROL MECHANISM FOR ROAD MACHINES Filed May 17, 1952 2 Sheets-Sheet l INVENTOR n e m G P e 9 r w 6 MN QM ATTORNEY G. P. GREEN Sept. 27, 1955 HYDRAULIC CONTROL MECHANISM FOR ROAD MACHINES 2 Sheets-Sheet 2 Filed May 17 George 1? Green INVENTOR ATTORNEY United States Patent Ofifice 2,718,831 Patented Sept. 27, 1955 HYDRAULIC CONTROL MECHANISM FOR ROAD MACHINES George P. Green, Lubbock, Tex.

Application May 17, 1952, Serial No. 288,477

3 Claims. (CI. 94-40) This invention relates to an improvement in road machines, and the principal object is to provide a machine of this class which may be advantageously applied in construction operation relative to road subgrades, base courses, surface courses and other work of similar nature such as terracing, leveling, compacting and miscellaneous construction of this nature. These and other objects are hereinafter more fully described, illustrated in the drawings, and specifically pointed out in the appended claims; it being understood that construction deviations may be made so long as they fall within the scope of the claims.

This application is a continuation-in-part of my copending application Serial No. 580,882, now Patent No. 2,601,277.

Figure l is an elevation of the right side of the machine.

Figure 2 is an elevational view of an hydraulic control for the steering arrangement.

Figure 3 is a vertical section along line 3-3, Figure 2.

Figure 4 is a front elevation, partly in section, of a portion at the front wheel of the machine.

- Figure 5 is a section through an hydraulic grade control mechanism, along line 55, Figure 6.

Figure 6 is an elevational view of an hydraulic grade control mechanism, along line 66, Figure 5; and

Figure 7 is an elevational view, partly in section, of a clutch for driving and steering the machine.

Similar numerals refer to similar parts throughout the several views.

In general, the machine comprises a horizontal frame provided with supporting wheels at each end, to travel along a strip of work, with the woodworking structure spanned transversely thereto; and a carriage frame roller mounted on the structure and supporting certain members such as a mixer, blades and rollers adapted to per form a sequence of road construction operations as the carriage is propelled back and forth across the work.

The travel rate of the entire machine along the strip of work is coordinated with the carriage travel, so that the operations lap to produce a uniformly worked section, all of which structure is illustrated and described fully in my Patent No. 2,601,277 and in my co-pending applications, Serial Numbers 278,249 and 278,250 filed March 24, 1952.

The invention herein described and claimed pertains to a special hydraulic mounting for the front wheel support of my road machine to vary the elevation of the front end of the machine relative to the wheels.

The structure which spans the work comprises two I beams, 1 and 2, which are hinged at the middle on hinges 3. The I beams are spaced and secured horizontally by suitable braces. The I beams are pivoted about hinges 3 by means of shaft 5, with eccentric portions connecting integral truss portions 6 of the beams. A crank 8 with a worm gear cooperates with gear 9 which is adapted to rotate shaft 5 and thus enable adjustment of the angle at which beams 1 and 2 meet at hinges 3. This is for the purpose of predetermining the crown of the road section under construction or repair.

The span structure is detachably fixed to girders 10, and braces 15, Fig. 1, by bolts (not shown) passing through holes in the contacting flanges of the members, the bolt holes being arranged along the I beams to permit fixing the girders 10 at optional positions to thus adapt the wheel tread to various widths, as well as to facilitate knock-down for transportation. Girders 10 are supported by a wheel arrangement on each end adapted to support the entire machine.

The rear wheels 11 are relatively wide for hearing and traction purposes. Axle 12 for wheel 11 is rotatively mounted in bearings 13 on frame members 14, which are fixed to girders 10. Braces 15 connect frame members 14 to beam 2 and are fixed to girders 10 by means of webs. A sprocket 17, Fig. 1, is fixed to each wheel 11 and cooperates with chain 18 to which power is transmitted to propel the machine.

Pneumatic front wheels 19, Figs. 1 and 4, are rotatably fixed to respective forks 20 from which a piston.21 extends into a cooperating hydraulic cylinder 22 (Fig. 4). A link 23, Fig. 1, fixed to front wheel fork 20 is adapted to be fixed at option to a bracket 24 which is rigidly fixed to cylinder 22 so that piston 21 is free for longitudinal motion and restrained from rotation on the cylinder 22.

As shown in my Patent No. 2,601,277, above identified, clutches are provided to steer and turn the machine by disengaging actuation on one side while the other side continues actuation. Details of the clutch are shown in Fig. 24, in which member 108 is secured to shaft 104 by set screw 109. Member 110 is arranged to rotate with member 108 by means of key 111 which is adapted to permit longitudinal motion of member 110 relative to 108. A lining 112 suitable for frictional contact is fixed to member 110. Member 113 which is adapted to cooperate with lining 112 is rotatably journaled on shaft 104 and maintained in position by collar 114. Spring 115 is arranged in compression between members 110 and 108 to maintain frictional contact between members 112 and 113 except when control is disengaged by application of force through control yoke 116 to compress spring 115. Rollers 117 are provided on each side of control 116 to cooperate with the flange portion of member 110 when the force is applied. Control yoke 116 is operated by a diaphragm power device 118 which is actuated by pressurized fluid introduced at passage 119. Sprocket 120, an integral portion of member 113, is provided to actuate drive chain 18, Fig. 1. Support 122 is fixed to brace member 15, and part 123 is secured to support 122 by bolts 124 to form a split bearing and rotatably support member 114.

Hydraulic fluid is supplied under pressure for operating device 118 of the clutches, Fig. 7, and to maintain front wheel piston 21, Fig. 4, in a predetermined position. No hydraulic fluid supply facilities are shown by the drawings, however any arrangement of conventional type may be applied.

An hydraulic fluid control valve for clutch members 108 is shown in Figs. 2, 3 and 4. A casing 125 is provided with an inlet fluid passage 126, a return passage 127, and passage 128 which is connected to passage 119 of one clutch, Fig. 7, by a suitable fluid conduit, and passage 129 which is similarly connected to the other clutch. An oscillatory valve member 130 (Fig. 2), is fixed to shaft 131 which is journaled in cover member 132 and casing 125 which latter is provided with packing 133. Passages 134, 135 and 136 in valve 130 are arranged so that when the valve is oscillated counterclockwise, pressurized fluid flows through passages 126, 135 and 128 to passage 119 of the clutch on the left side of the machine, while passage 119 of the other clutch is connected to the return line through passages 129, 134

structure portion 6, by screws 335 (Fig. l).

and 127. When valve 130 is oscillated clockwise (Fig. 2) passages '128 and 129 are reverse in function, 128 being in the return circuit and 129 the pressurized circuit.

Anarm 137, Figs. 3 and 4, is fixed to shaft 131 and connected by control link 138 to guide arm 13) which is fulcrumed to one end of member 14% which is fixed to the machine at the other end, as shown in Fig. 4. The purpose of this arrangement is to provide a means to steer the machine automatically by guide wheel 141 of guide arm 139, following a guide line arranged along the work, and thus causing valve 134) to function as the machine deviates from the course determined by the guide-line to disengage the clutch and drive wheel 11 came applicable side so that the other drive wheel 11 propels the machine about the disengaged wheel ll as a pivot until the machine is brought to a true course. It is advantageous to adapt this control valve to operate on either side of the machine, at option, and also to provide a manual means of control. Guide arm 139 and member 140 also serve to maintain the machine on a predetermined grade as described hereinafter.

An automatic hydraulic means, for controlling the grade at which the machine operates by regulating the height of girders 10 above front wheels 19 through piston 21 (Figs. 1 and 4), is provided. Rear Wheels Ill travel on the completed surface in most applications.

An hydraulic control valve for elevation control comprises casing 310 with a detachable top 311 (Figs. 4, and 6) contains float 312 connected by arm 313 to shaft 314 which is connected by arm 315 (Fig. 5) which cooperates with pin 316 (Fig. 6). Through pin 316 (Fig. 5) and arm 317, a rotary valve 318, fixed to shaft 319, is pivoted in operative range. Passage 320 is connected by a fluid line to a pressurized fluid source, passage 321 to wheel cylinder 22, and passage 322 to a low pressure return line as illustrated in Pig. 6. The above valve functions to introduce or to return hydraulic fluid from wheel cylinder 22. The control valves are slidable vertically on guide 324 by cooperation with screws 325 which bears on girders it by part 326 (Figs. 1 and 4). Screw 325 is operated by pulleys 327 and 328 coupled by cable 329 (Fig. l). The control valve casings 3H are connected at passages 330 (Fig. 6) to a fluid line (not shown) and a fluid reservoir 332 is connected to said fluid line by flexible fluid conveying line 333 through a valve shown in my patent above identified. Fluid reservoir 332 is shifted vertically on guide 335 fixed to span Grade control is accomplished by the fluid maintaining a common level in the valve casings and reservoir 332 by gravity flow through the interconnecting fluid conveying lines, the valve being actuated by a change in fluid level to cause hydraulic shifting of piston 21 (Fig. l) in a direction to tend to maintain a predetermined level of fluid in the valve casings.

The machine may be controlled by a wire or other suitable means placed on a predetermined grade line to guide wheel 14! (Fig. 4) and thus actuate valve 31 through arm 139, member me, and link 3325 connected to pin 316 (Fig. 6).

The above description and drawings are merely an illustration of my invention in one of many possible forms of application, and the scope of protection contemplated is to be taken from the appended claims interpreted as broadly as is consistent'with the prior art.

What is claimed is:

1. In a machine of the class set forth, a wheel supported structure, power means to propel said machine along a predetermined course, equipment adapted to perform construction operations of the class set forth supported relative to said structure, wheel supports provided with hydraulic actuated means adapted to vary the elevation relation between said structure and cooperative wheels, float actuated hydraulic fluid control valve arranged to cooperate with said hydraulic actuated means,

a chamber and fluid for said float supported relative to said structure in the proximity of related wheel support, fluid conduit interconnection between the float chamber and a float fluid reservoir supported on said structure at a vantage point remote to said float chamber, a pressurized fluid supply and return means connected through said control valve to cooperative wheel support hydraulic actuated means in a manner such that deviations in level of float fluid in the float chamber causes the wheel support hydraulic actuated means to raise or lower the structure and conjunctive float chamber as applicable to cause float fluid to flow between said float chamber and reservoir to maintain a predetermined fluid level in each, means to predetermine the relative elevations between the structure, the fluid reservoir, and the float chamber.

2. In a machine of the class set forth, equipment adapted to perform construction operations of the nature set forth supported relative to a structure, support wheels arranged at the rear of the structure adapted to cooperate therewith in a manner to travel on Work completed by the machine, front wheels, one on each side, arranged to support the structure through supports, each front wheel support provided with hydraulic actuated means adapted to vary the elevation relation between the structure and respective front wheel, a pressurized fluid supply and return means connected through a float actuated fluid control valve to cooperative Wheel support hydraulic actuated means, a float chamber and fluid for the float of each valve supported relative to said structure in the proximity of each respective front wheel support, fluid conduit interconnection with a float fluid reservoir supported on the structure back of the float chambers and in the proximity of the rear support wheels, all adapted such that deviations in level of float fluid in either float chamber causes the Wheel support hydraulic actuated means to raise or lower the structure and conjunctive float chamber as applicable to cause float fluid to flow between said float chambers and the reservoir to maintain a predetermined fluid level in each, means to predetermine the relative elevations between the structure, the fluid reservoir, and the two float chambers, power means to propel said machine along a predetermined course.

3. In a machine of the class set forth, equipment adapted to perform construction operations of the'class set forth supported relative to a structure support, wheels arranged at the rear of the structure adapted to cooperate therewith in a manner to travel on work completed by the machine, front wheels, one on each side arranged to support the structure through supports, each front wheel support provided with hydraulic actuated means adapted to vary the elevation relation between the structure and respective front wheel, a pressurized fluid supply and return means connected through a fluid control valve to cooperate with each wheel support hydraulic actuated means, a float and float chamber with float fluid supported in the proximity of one front wheel and adapted to actuate the related fluid control valve, said float cha1nher interconnected by a fluid conduit with a fluid reservoir supported on the structure transversely across from the float chamber, all in a manner such that deviations in relative elevation of the reservoir to the float chamber causes the cooperative wheel support hydraulic actuated means to raise or lower the structure and conjunctive float chamber as applicable to cause float fluid to flow between said float chamber and the reservoir to maintain a predetermined fluid level in each, means provided to predetermine the relative elevations between the structure, the reservoir and float chamber, control linkage provided to actuate the other fluid control valve which is not float actuated, said linkage adapted for contact cooperation with a grade guide line arranged along a predetermined course, said linkage and control valve adapted in a manner such as to control the hydraulic fluid actuation of the related hydraulic actuated means to vary the elevation relation between said structure and wheel support as applicable to maintain a predetermined elevation relation between the portion of structure in the proximity of the wheel thus controlled and guide grade line, power means to propel said mechanism along the predetermined course.

References Cited in the file of this patent UNITED STATES PATENTS 901,055 Allen et a1. Oct. 13, 1908 

